Gasdynamics and Heat Transfer Modeling in Rocket Joints

A new thermal-flow simulation code has been developed to model the gasdynamics and heat transfer, as well as O-ring and flow path erosions inside the Space Shuttle solid rocket motor joints by combining a thermal analyzer and a general-purpose computational fluid dynamics code. The pressure, temperature, and velocity of the combustion gas in the leak paths are obtained by solving the time-dependent Navier-Stokes equations, whereas the solid temperature is calculated using the heat conduction equation. The gas and solid are coupled by the heat flux at the solid-gas interface. The results of a few test cases are compared with exact solutions or experimental data. These cases include both steady and transient problems involving area change, friction, and heat transfer between gas and solid, as well as mass addition due to the erosion of solid wails. In addition, a set of Space Shuttle solid rocket motor nozzle joint-4 subscale hot-flow tests is modeled, and the predicted pressures, temperatures (both gas and solid), and O-ring erosions are compared with the measured data. (Author)